The present disclosure relates to a vehicle seat, and more particularly to a vehicle seat including a side support device that assists a vehicle exit movement of an occupant.
Hitherto, there is known a vehicle seat including a side support device that supports a side portion, which is in a seat widthwise direction in a seat cushion on which an occupant can seat, to be movable between a standing position provided so that a sitting surface is protruded from a center portion in the seat widthwise direction and a vehicle exit assist position provided so that the sitting surface is recessed from the center portion. When the side portion of the seat cushion is supported in the standing position by the side support device, a holding property for the occupant can be increased when the occupant is sitting. Then, when the side portion is supported in the vehicle exit assist position, a load imposed on the occupant who is moving over the side portion can be decreased when the occupant opens a door of the vehicle for entry/exit.
For example, a vehicle seat provided with an entry/exit support device described in Japanese Patent Publication JP S61-57435A includes i) a side frame that supports a side portion of a seat cushion to be movable between a standing position and a lowered position and ii) a lock mechanism that locks the side frame when a sitting load of an occupant is imposed on a center portion of the seat cushion. Specifically, the lock mechanism is configured to lock the side portion in the standing position when the occupant is sitting on a seat main body, and release the lock of the side frame when the occupant stands up for the entry/exit.
Moreover, a vehicle seat including an entry/exit support device described in Japanese Patent Publication JP 2007-282746A includes a cushion holder that supports a side support cushion to be movable between a standing position and an inclined position, a standing hold device that holds the cushion holder in the standing position, and a standing hold release device that release a standing hold state of the cushion holder, thereby moving the cushion holder from the standing position to the inclined position. Specifically, when the vehicle door is opened for the occupant to enter/exit, the standing hold state of the cushion holder is released, and when the vehicle door is closed after the occupant enters/exits, the cushion holder is returned to the standing hold state.
Moreover, a vehicle seat including an entry/exit support device described in Japanese Patent Publication JP H7-163439A includes a seat deflection sensor that detects a state where an occupant is sitting on a seat main body, a door switch that detects an opening/closing operation of a vehicle door by the occupant, a belt fastening switch that detects a state where the occupant has fastened a seat belt, and the like, for example. Further, this vehicle seat includes a control device that receives information from the various sensors and the various switches, and controls an operation of the entry/exit support device.
Incidentally, each of the entry/exit support devices described in JP S61-57435A, JP 2007-282746A, JP H7-163439A is configured to lock the side portion in the standing position and to release the lock in accordance with the sitting movement of the occupant or the opening/closing operation of the vehicle door. However, in some scenarios, the side portion needs to be locked in the standing position in a state other than the entry/exit of the occupant into/from the vehicle. A reason for this is that, for example, the side portion of the seat cushion inclines, and the holding property for the sitting occupant may thus be impaired when the occupant moves to slightly stand up from the seat main body, or the occupant moves to open the vehicle door in a state where the occupant remains sitting.
Moreover, it is generally desired for the occupant to be supported by the entry/exit support device particularly during the exit from the vehicle. Therefore, there is a need for an entry/exit support device capable of particularly more surely assisting the vehicle exit movement of the occupant.